1999 "EE" Evinrude 70HP 4-Stroke Service Manual, P/N 787023, Page 158Get this manual
Cleaning and Inspection &
Replace damaged componentsShift system failure will cause loss of control over direction of engine thrust1Discard all seals, O-rings, gaskets, and the clutch dog spring
Clean all gearcase components in solvent and dry with compressed airTo avoid injury, wear eye protection and regulate air pressure to not more than 25 PSI (172 kPa)After cleaning, coat all internal components with OMC Ultra-HPF gearcase lube to prevent rusting
3Perform the following inspections: Gearcase housingall gasket surfaces must be free of gasket materialAll threaded holes must be free of corrosion and sealerUpper driveshaft oil circulation hole must be clearWater intake screensmust be clearIf they can't be cleaned, they must be replacedInstall water intake screens, screws, and nutsif anodes have eroded to two-thirds their original size, they must be replaced41859
W Gearcase anodes -
Driveshaftcheck threads and splines for chips, wear, and cracksBearing and gear surfaces must not show signs of fretting, corrosion, or discolorationSevere spline wear indicates the exhaust housing or gearcase is distorted, possibly by impact damage All internal componentsmust be inspected for signs of wear, distortion, chipping, fretting, pitting, galling, and discoloration due to improper lubrication48909